In known dispensing packings, the hollow body exhibits a substantially cylindrical shape with a circular cross-section and the driving member is shaped as a knurled part for rotating the screw, which causes the axial displacement of the piston. The driving member is mounted at the lower end of the body in axially aligned relationship with the latter and exhibits an external cylindrical shape corresponding to that of the hollow body so that its external peripheral surface extends that of the body. It is thus easy to manually turn the knurled pat since the elements for rotary driving of the latter are freely accessible.
Known dispensing packing have major inconvenience in that these component elements and devices require a cylindrical shape with a circular cross-section.